A subclinical infection is an infection that, being subclinical, is nearly or completely asymptomatic. A subclinically infected person is thus an asymptomatic carrier of a microbe, intestinal parasite, or virus that usually is a pathogen causing illness, many pathogens spread by being silently carried in this way by some of their host population. Such infections occur both in humans and nonhuman animals, an example of an asymptomatic infection is a mild common cold that is not noticed by the infected individual. Since subclinical infections often occur without eventual overt sign, their existence is only identified by microbiological culture or DNA techniques such as polymerase chain reaction, an individual may only develop signs of an infection after a period of subclinical infection, a duration that is called the incubation period. This is the case, for example, for sexually transmitted diseases such as AIDS. Individuals with such subclinical infections, and those that never develop overt illness, they are evolved physiological and behavioral responses of the host to clear itself of the infection.
Instead of incurring the costs of deploying these evolved responses to infections, Subclinical infections are important since they allow infections to spread from a reserve of carriers. They can cause clinical problems unrelated to the issue of infection. For example, in the case of urinary infections in women. Endara, Trueba, Solberg, Owen D. Bates, Sarah J. Ponce, Cevallos, Matthijnssens, Eisenberg and Subclinical Infection with Rotavirus PG9, Rural Ecuador
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are called subclinical infections, other diseases might be considered subclinical if they present some but not all of the symptoms required for a clinical diagnosis. The term clinically silent is used, knowing that a condition is asymptomatic is important because, It may develop symptoms and so require watch and wait or early treatment. It may resolve itself or become benign and it is required that a person undergoes treatment so it does not cause medical problems such as high blood pressure and hyperlipidaemia. Be alert to possible problems, asymptomatic hypothyroidism makes a person vulnerable to Wernicke-Korsakoff syndrome or beri-beri following intravenous glucose, the affected person may be infectious and unknowingly spread the infection to others.
An example of a disease is Cytomegalovirus which is a member of the herpes virus. It is estimated that 1% of all newborns are infected with CMV, in some diseases, the proportion of asymptomatic cases can be important. For example in multiple sclerosis it is estimated that around 25% of the cases are asymptomatic, asymptomatic conditions may not be discovered until the patient undergoes medical tests. Some people may remain asymptomatic for a long period of time. If a patient is asymptomatic, precautionary steps must be taken, a patients individual genetic makeup may delay or prevent the onset of symptoms. Some diseases are defined only clinically, like AIDS being opposed to HIV infection, therefore it makes no sense to speak about asymptomatic AIDS. This concept of clinically defined diseases is related in some way to the concept of syndrome and these are conditions for which there is a sufficient number of documented individuals that are asymptomatic that it is clinically noted. For a complete list of asymptomatic infections see subclinical infection
International Standard Book Number
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay.
The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces.
Separating the parts of a 10-digit ISBN is done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
Medicine is the science and practice of the diagnosis and prevention of disease. The word medicine is derived from Latin medicus, meaning a physician, Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Medicine has existed for thousands of years, during most of which it was an art frequently having connections to the religious and philosophical beliefs of local culture. For example, a man would apply herbs and say prayers for healing, or an ancient philosopher. In recent centuries, since the advent of modern science, most medicine has become a combination of art, while stitching technique for sutures is an art learned through practice, the knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science. Prescientific forms of medicine are now known as medicine and folk medicine. They remain commonly used with or instead of medicine and are thus called alternative medicine.
For example, evidence on the effectiveness of acupuncture is variable and inconsistent for any condition, in contrast, treatments outside the bounds of safety and efficacy are termed quackery. Medical availability and clinical practice varies across the world due to differences in culture. In modern clinical practice, physicians personally assess patients in order to diagnose, the doctor-patient relationship typically begins an interaction with an examination of the patients medical history and medical record, followed by a medical interview and a physical examination. Basic diagnostic medical devices are typically used, after examination for signs and interviewing for symptoms, the doctor may order medical tests, take a biopsy, or prescribe pharmaceutical drugs or other therapies. Differential diagnosis methods help to rule out conditions based on the information provided, during the encounter, properly informing the patient of all relevant facts is an important part of the relationship and the development of trust.
The medical encounter is documented in the record, which is a legal document in many jurisdictions. Follow-ups may be shorter but follow the general procedure. The diagnosis and treatment may take only a few minutes or a few weeks depending upon the complexity of the issue, the components of the medical interview and encounter are, Chief complaint, the reason for the current medical visit. They are in the patients own words and are recorded along with the duration of each one, called chief concern or presenting complaint. History of present illness, the order of events of symptoms. Distinguishable from history of illness, often called past medical history
Sensitivity and specificity
Specificity measures the proportion of negatives that are correctly identified as such. Because most medical tests do not have sensitivity and specificity values above 99%, but for practical reasons, tests with sensitivity and specificity values above 90% have high credibility, albeit usually no certainty, in differential diagnosis. Sensitivity therefore quantifies the avoiding of false negatives, and specificity does the same for false positives and this trade-off can be represented graphically using a receiver operating characteristic curve. In reality, any non-deterministic predictor will possess a minimum error bound known as the Bayes error rate, imagine a study evaluating a new test that screens people for a disease. Each person taking the test either has or does not have the disease, the test outcome can be positive or negative. The test results for each subject may or may not match the actual status. The four outcomes can be formulated in a 2×2 contingency table or confusion matrix, as follows, Sensitivity refers to the tests ability to correctly detect patients who do have the condition.
In the example of a medical test used to identify a disease, a high sensitivity test is reliable when its result is negative, since it rarely misdiagnoses those who have the disease. A test with 100% sensitivity will recognize all patients with the disease by testing positive, a negative test result would definitively rule out presence of the disease in a patient. A positive result in a test with high sensitivity is not useful for ruling in disease, suppose a bogus test kit is designed to show only one reading, positive. When used on diseased patients, all patients test positive, giving the test 100% sensitivity, sensitivity by definition does not take into account false positives. The bogus test returns positive on all healthy patients, giving it a positive rate of 100%. The calculation of sensitivity does not take into account indeterminate test results, if a test cannot be repeated, indeterminate samples either should be excluded from the analysis or can be treated as false negatives. Specificity relates to the ability to correctly detect patients without a condition.
Consider the example of a medical test for diagnosing a disease, Specificity of a test is the proportion of healthy patients known not to have the disease, who will test negative for it. The test rarely gives positive results in healthy patients, a test with 100% specificity will read negative, and accurately exclude disease from all healthy patients. A positive result signifies a high probability of the presence of disease, a test with a higher specificity has a lower type I error rate. If 100 patients known to have a disease were tested, and 43 test positive, if 100 with no disease are tested and 96 return a negative result, the test has 96% specificity
Medical diagnosis is the process of determining which disease or condition explains a persons symptoms and signs. It is most often referred to as diagnosis with the context being implicit. The information required for diagnosis is typically collected from a history, one or more diagnostic procedures, such as diagnostic tests, are done during the process. Sometimes Posthumous diagnosis is considered a kind of medical diagnosis, Diagnosis is often challenging, because many signs and symptoms are nonspecific. For example, redness of the skin, by itself, is a sign of many disorders, thus differential diagnosis, in which several possible explanations are compared and contrasted, must be performed. This involves the correlation of various pieces of information followed by the recognition and differentiation of patterns, occasionally the process is made easy by a sign or symptom that is pathognomonic. Diagnosis is a component of the procedure of a doctors visit. From the point of view of statistics, the procedure involves classification tests.
The first recorded examples of medical diagnosis are found in the writings of Imhotep in ancient Egypt, a Babylonian medical textbook, the Diagnostic Handbook written by Esagil-kin-apli, introduced the use of empiricism and rationality in the diagnosis of an illness or disease. Traditional Chinese Medicine, as described in the Yellow Emperors Inner Canon or Huangdi Neijing, specified four diagnostic methods, auscultation-olfaction, hippocrates was known to make diagnoses by tasting his patients urine and smelling their sweat. This article uses diagnostician as any of these person categories, a diagnostic procedure does not necessarily involve elucidation of the etiology of the diseases or conditions of interest, that is, what caused the disease or condition. Such elucidation can be useful to optimize treatment, further specify the prognosis or prevent recurrence of the disease or condition in the future, the initial task is to detect a medical indication to perform a diagnostic procedure.
Indications include, Detection of any deviation from what is known to be normal, such as can be described in terms of, for example, physiology, psychology, a complaint expressed by a patient. The fact that a patient has sought a diagnostician can itself be an indication to perform a diagnostic procedure, even during an already ongoing diagnostic procedure, there can be an indication to perform another, diagnostic procedure for another, potentially concomitant, disease or condition. A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease, Diagnostic tests can be used to provide prognostic information on people with established disease. Processing of the answers, findings or other results, consultations with other providers and specialists in the field may be sought. There are a number of methods or techniques that can be used in a diagnostic procedure, in reality, a diagnostic procedure may involve components of multiple methods. The final result may remain a list of possible conditions, the resultant diagnostic opinion by this method can be regarded more or less as a diagnosis of exclusion
The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It.
Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing.
The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
In medicine, relapse or recidivism is a recurrence of a past condition. For example, multiple sclerosis and malaria often exhibit peaks of activity and sometimes periods of dormancy. In the context of use, relapse or reinstatement of drug-seeking behavior, is a form of spontaneous recovery that involves the recurrence of pathological drug use after a period of abstinence. Relapse is often observed in individuals who have developed an addiction or either form of drug dependence. Substances that may cause addiction or dependence include, Stimulants increase activity in the cerebral cortex leading to increased motor activity, cocaine Amphetamine Methamphetamine Depressants slow down neuronal activity. Benzodiazepines Opioids activate or block opioid receptors in the brain typically to reduce the effect of pain and this can lead to decreased ability to perceive and evaluate risks and make good decisions, and other characteristics of what is commonly known as intoxication. Nicotine is neither a stimulant nor a depressant but rather a chemical that is absorbed by the skin, the Drug Enforcement Administration has categorized controlled substances into 5 major categories based on the drug’s intended use and potential for addiction and dependence.
Drugs with the highest addictive potential are listed in DEA Schedules I, the addictive potential of a drug varies greatly between substances and is based on both the rewarding and reinforcing properties of a drug. Addictive drugs tend to induce euphoria, otherwise known as a drug high, the three main categories of harm are the physical harm of the drug to the user, the drug’s tendency to cause dependence, and effects of the drug on society. The first category can be divided into three parameters of harm, acute physical harm, chronic physical harm, and intravenous harm. Acute harm is defined as the effects associated with use of the given drug such as respiratory depression or myocardial infarction. Chronic harm is the consequence of continued and repeated use such as psychosis or lung disease, intravenous harm refers to problems associated with the route of administration such as the spread of blood-borne pathogens like HIV. The second parameter of harm is subdivided into two categories, the physical dependence and psychological dependence and this category is subdivided into the last three parameters, other social harms, and healthcare costs.
These parameters attempt to rate a drug’s impact on families, the D2 receptor availability has an inverse relationship to vulnerability to the reinforcing effects of the drug. That is, as D2 receptors become limited the user becomes more susceptible to the effects of cocaine. It has noted that D2 receptors may return to the level existing prior to drug exposure during long periods of abstinence. Social interactions, such as the formation of dominance hierarchies. Socially dominant animals exhibit higher availability of D2 receptors and fail to maintain self-administration and these factors may induce a neurochemical response in the drug taker that mimics the drug and thus triggers reinstatement